I have an intel NUC D54250WYK running latest non-testing arch.
linux minikat 3.17.3-1-ARCH #1 SMP PREEMPT Fri Nov 14 23:13:48 CET 2014 x86_64 GNU/Linux
I have two PCTV 290e cards. Both of these work fine running alone (ie using just /dev/dvb/adapter0 or adapter1). However, when I run both together all my usb devices seem to disappear. Using the power button I can shut the system down.
Searching reveals a similar problem here https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1306712.
It doesn't seem to matter which device is used second or which application is using them; ie 2 x vlc or vlc + tzap etc etc all seem to cause the problem.
I used the same devices on my old acer revo 3610 and they work fine together there. I attach some information from the journal.
This bug currently makes the system unusable as a TV recorder. I think I have the latest BIOS for this device (WYLPT10H.86A.0030.2014.0919.1139).